Sealing device

Abstract

To prevent falling away of a backup ring ( 3 ) from a main lip ( 12 ) when uninstalled to a device and prevent inverse assembling, a sealing device is provided with an attaching ring ( 11 ), a main lip ( 12 ) integrally provided on an inner periphery of the attaching ring, and a backup ring ( 3 ) supported to a backup ring support portion ( 15 ) formed on an inner periphery of the main lip ( 12 ) so as to be positioned at an atmospheric air side than a sliding surface with a shaft, the backup ring support portion ( 15 ) and the backup ring ( 3 ) are fitted to each other with their fitting surfaces ( 15 a , 31 a ) which become smaller in diameter relatively toward an outer side in an axial direction, whereby the backup ring ( 3 ) is fitted to the backup ring support portion ( 15 ) and has directionality in the fitting surfaces ( 15 a , 31 a ).

1 . A sealing device comprising:
 an attaching ring;   a main lip integrally provided on an inner periphery of the attaching ring, and slidably brought into close contact with an outer peripheral surface of a shaft in a state of being directed to an inner side in an axial direction; and   a backup ring which is supported to a backup ring support portion formed on an inner periphery of said main lip so as to be positioned at an atmospheric air side than a sliding surface with said shaft, and bears said main lip from the atmospheric air side and the inner peripheral side,   wherein the backup ring support portion of said main lip and an outer peripheral portion of said backup ring are fitted to each other with their fitting surfaces which become smaller in diameter relatively toward an outer side in an axial direction.   
   
   
       2 . A sealing device as claimed in  claim 1 , wherein an introduction surface, which becomes larger in diameter toward an outer side in the axial direction, is formed at an outer side in the axial direction than the fitting surface to the backup ring on the inner peripheral surface of the backup ring support portion.